The Second Cargese School on Earthquakes - Participant Support

Stanford University, Stanford CA

Investigators

Abstract

Advances in the last decade have led towards a more complete picture of earthquake processes. The quality and quantity of data available to study earthquakes is increasing rapidly and both the availability of those observations and the capacity of computers to them have improved dramatically. Recent earthquakes are providing the research community with exceptionally rich datasets with which to explore earthquake behavior. Some of these data indicate an extended and complex earthquake initiation process that may involve previously unrecognized slow fault slip. The second Cargèse School on Earthquakes will provide focused yet diverse perspectives on our understanding of earthquakes. These will be delivered as lectures by leading earthquake scientists from around the world who are working at the cutting-edge of earthquake research. Lectures will be combined with hands-on tutorials that focus on learning new analysis methods and software. The school is intended to stimulate the emergence of a broader understanding of the current issues, and is aimed particularly at engaging young scientists (students and post-docs), and will thus facilitate future collective momentum towards earthquake preparedness and forecasting. This proposal would provide partial travel support for scientists from US institutions. The costs of participation by US scientists are highly leveraged against the costs of hosting the school, which are covered through European funding sources. The second Cargèse School on Earthquakes will provide instruction on the state-of-the-art covering three main research topics: (1) Earthquake Nucleation. Earthquakes are the culmination of accelerating processes that may manifest as growing aseismic slip, as confirmed by laboratory rock mechanics experiments, often accompanied by foreshocks, tremor, or other seismic phenomena. Recent observations of these and how they scale with magnitude suggest earthquake size may be influenced by the nucleation process. (2) Earthquake Triggering and Rupture. New opportunities to discover what triggers earthquakes include: (A) experimentation on real crustal faults under anthropogenic forcing, principally wastewater injection, and its consequent increase in seismicity rates and (B) the development of new methods to image in four dimensions the physical conditions and properties that determine which fault slip mode is likely to dominate. There are also open questions to be addressed concerning how geometrical/structural configurations and past history influence rupture propagation. Discoveries relevant to these opportunities and others will be discussed. (3) Beyond Earthquakes - Completing the Slip Spectrum. Slow aseismic slip acts to relieve stress applied to faults and to accelerate stress accumulation on neighboring stuck fault patches that eventually break and radiate seismic waves. Innovative seismic waveform and statistical analyses have served as proxies for the more difficult to observe aseismic slip, which is an ongoing challenge. These include verification of the proxy status by detecting aseismic deformation directly and evaluation of how seismic and aseismic modes interact.